Optimized Self‐Templating Synthesis Method for Highly Crystalline Hollow Cu₂O Nanoboxes

Abstract

Hollow nanostructures have garnered great interest by virtue of their broad applications and outstanding performances in catalysis, [1,2] energy storage, [3-5] drug delivery, [6] and other aspects. In recent years, the central concern in this area has shifted to developing advanced methods for constructing

Layer‐by‐Layer Electrodeposition of FTO/TiO2/CuxO/CeO2 (1 <x< 2) Photocatalysts with High Peroxidase‐Like Activity by Greatly Enhanced Singlet Oxygen Generation

“…As for FTO/TiO 2 , its O lat peak appeared at 529.8 eV that should be ascribed to TiO 2 ; [ 32–35 ] however, in FTO/TiO 2 /Cu 2 O, it blueshifted to 530.5 eV that was consistent with the O lat peak of Cu 2 O. [ 20–24,26 ] This is an evidence to identify the formation of TiO 2 /Cu 2 O pn‐heterojunction. Interestingly for FTO/TiO 2 /Cu x O/CeO 2 , the O lat peak shifted back to 529.6 eV, and meanwhile the peak values of O act redshifted from 532.1 to 531.8 eV, because the O lat binding energy of CuO and CeO 2 are 529.6 and 529.0 eV, respectively, indicating its more reactive oxygen environment owing to the strong coupling of Cu x O/CeO 2 compared to others.…”

“…[ 32 ] The shift of the Ti 2p peak position should be influenced by the content of Cu 2 O in TiO 2 /Cu 2 O pn‐heterojunction, that is, the more surface deposited Cu 2 O the higher binding energy of Ti 2p orbits would be. [ 35 ] In Figure 1c, the signal of Cu + in FTO/TiO 2 /Cu 2 O should be ascribed to Cu 2p 3/2 (932.5 eV) and Cu 2p 1/2 (952.5 eV) in accordance with those of bulk Cu 2 O; [ 20,23,24 ] however, the curve of FTO/TiO 2 /Cu x O/CeO 2 could be fitted into obvious characteristic signals of Cu 2+ besides those of Cu + , proving the partial oxidation of Cu 2 O into CuO during etching. [ 37,38,42 ] In addition, FTO/TiO 2 /Cu x O/CeO 2 shows complex signals that V 1 (885.2 eV) and U 1 (903.7 eV) should be related to Ce 3+ , while V (882.6 eV), V 2 (888.8 eV) and V 3 (898.5 eV) of Ce 3d 5/2 , and U (901.1 eV), U 2 (907.5 eV) and U 3 (916.9 eV) of Ce 3d 3/2 belonged to Ce 4+ , indicating the stable existence of Ce 3+ ions in CeO 2 .…”

“…As seen in Figure S1d, Supporting Information, FTO/TiO 2 was changed from white to yellow after loading Cu 2 O that was in a cubic phase judged by XRD (Figure S3, Supporting Information). [20,24,26] The existence of Cu elements on TiO 2 could be also identified by comparing the EDS spectra of FTO/TiO 2 and FTO/TiO 2 /Cu 2 O (Figures S2 and S4, Supporting Information). The SEM images in Figure S5, Supporting Information, demonstrated that the amount of Cu 2 O was increased with the electrodeposition cycles, and the edges of TiO 2 nanosheets had been fully covered after the forth repeated deposition.…”

“…[19] More importantly, Cu 2 O has the advantages of non-toxicity, large natural reserves, multiple preparation methods, and low cost, so it is very promising to be employed for photocatalysis. [20][21][22][23][24][25][26] However, there commonly exists an inevitable problem for semiconductor materials caused by fast recombination of photogenerated carriers. In order to suppress recombination, an effective way was to fabricate pn-heterojunction to promote migration of excited electrons (e − ) from the p-type component to its n-type counterpart across their interfaces, realizing more efficient separation of carriers and hence improvement of photocatalytic activity.…”

“…[ 19 ] More importantly, Cu 2 O has the advantages of non‐toxicity, large natural reserves, multiple preparation methods, and low cost, so it is very promising to be employed for photocatalysis. [ 20–26 ]…”